Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH DRILLING; MINING
  • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/12—Packers; Plugs
  • E21B33/1208—Packers; Plugs characterised by the construction of the sealing or packing means
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH DRILLING; MINING
  • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/12—Packers; Plugs
  • E21B33/127—Packers; Plugs with inflatable sleeve
  • E21B33/1277—Packers; Plugs with inflatable sleeve characterised by the construction or fixation of the sleeve

Definitions

• the field of this invention relates to downhole packers and plugs that use a swelling element and more particularly to design that delay the onset of swelling once the element is run downhole.
• Figure 2a shows a wrapping 110 over a swelling material 102.
• Paragraph 20 reveals the material 110 can be removed mechanically by cutting or chemically by dissolving or by using heat, time or stress or other ways known in the art.
• Barrier 110 is described in paragraph 21 as an isolation material until activation of the underlying material is desired. Mechanical expansion of the underlying pipe is also contemplated in a variety of techniques described in paragraph 24.
• the protective layer 145 avoids premature swelling before the downhole destination is reached.
• the cover does not swell substantially when contacted by the activating agent but it is strong enough to resist tears or damage on delivery to the downhole location.
• pipe expansion breaks the covering 145 to expose swelling elastomers 140 to the activating agent.
• the protective layer can be Mylar or plastic.
• the packing element is an elastomer that is wrapped with an imperforate cover.
• the coating retards swelling until the packing element is actuated at which point the cover is "disrupted” and swelling of the underlying seal can begin in earnest, as reported in Column 7.
• the one in Figure 26 is foam that is retained for run in and when the proper depth is reached expansion of the tubular breaks the retainer 272 to allow the foam to swell to its original dimension.
• a permeable outer layer 10 covers the swelling layer 12 and has a higher resistance to swelling than the core swelling layer 12. Specific material choices are given in paragraphs 17 and 19. What happens to the cover 10 during swelling is not made clear but it presumably tears and fragments of it remain in the vicinity of the swelling seal.
• the swelling element is covered in treated burlap to delay swelling until the desired wellbore location is reached.
• the coating then dissolves of the burlap allowing fluid to go through the burlap to get to the swelling element 24 which expands and bursts the cover 20, as reported in the top of Column 8)
• a seal stack to be inserted in a seal bore of a downhole tool is covered by a sleeve shearably mounted to a mandrel.
• the sleeve is stopped ahead of the seal bore as the seal first become unconstrained just as they are advanced into the seal bore.
• An inflatable packer is filled with material that swells when a swelling agent is introduced to it.
• a packer has a fluted mandrel and is covered by a sealing element. Hardening ingredients are kept apart from each other for run in. Thereafter, the mandrel is expanded to a circular cross section and the ingredients below the outer sleeve mix and harden. Swelling does not necessarily result.
• Figure 3b shows a swelling component 230 under a sealing element 220 so that upon tubular expansion with swage 175 the plugs 210 are knocked off allowing activating fluid to reach the swelling material 230 under the cover of the sealing material 220.
• a water expandable material is wrapped in overlapping Kevlar sheets. Expansion from below partially unravels the Kevlar until it contacts the borehole wall.
• Clay is covered in rubber and a passage leading from the annular space allows well fluid behind the rubber to let the clay swell under the rubber.
• Water is stored adjacent a swelling material and is allowed to intermingle with the swelling material under a sheath 16.
• An exposed rubber sleeve swells when introduced downhole.
• the tubing or casing can also be expanded with a swage.
• a porous sleeve over a perforated pipe swells when introduced to well fluids.
• the base pipe is expanded downhole.
• a swelling material 16 around a pipe is introduced into the wellbore and swells to seal the wellbore.
• Alternating exposed rings that respond to water or well fluids are provided for zone isolation regardless of whether the well is on production or is producing water.
• Bentonite clay rings are dropped downhole and swell to seal the annular space, in these two related patents.
• Base pipe openings are plugged with a material that disintegrates under exposure to well fluids and temperatures and produces a product that removes filter cake from the screen.
• Figure 10 of this patent has two materials that are allowed to mix because of tubular expansion between sealing elements that contain the combined chemicals until they set up.
• Shape memory foam is configured small for a run in dimension and then run in and allowed to assume its former shape using a temperature stimulus.
• a swelling element rate regulation technique and product features an outer coating on a core of an element.
• the core is reactive to hydrocarbons or water depending on how it is configured.
• the surrounding coating is preferably formed of fine ground particles of a non-swelling polymer mixed in a solvent such as methyl-ethyl-ketone that is applied in a thin layer to the core exterior.
• This uncured outer layer is then contacted by a patterned surface.
• the patterned surface is pressed firmly against the uncured polymer/solvent mixture and transfers an inverse of the pattern to the surface of the coating. As pressure is applied, heat may also be applied to cure the coating.
• the resulting pattern is designed such that openings in the coating are created that regulate infiltration of water or other fluids through it and, as a result, the rate of swelling in the wellbore.
• Swell rate in governed in part by the ratio of the exposed area of the swelling compound to the total volume of the swelling compound. The smaller this ratio, the slower the rate of swell.
• the pattern created in the non-swelling layer may also provide limited mechanical restraint of the swelling element, further slowing the process.
• Figure 1 is a perspective view showing the element with the outer coating and the surrounding weave material.
• Figure 1 shows a cylindrically shaped core 10 that can be configured to be water reactive or hydrocarbon reactive.
• the bulk of the core 10 is a nitrile-based polymer with incorporated water absorbing particles.
• SAP super absorbing particles
• SAP super absorbing particles
• the core can be hydrocarbon reactive and made from an oleophillic polymer that absorbs hydrocarbons into its matrix.
• the swelling occurs from the absorption of the hydrocarbons which also lubricates and decreases the mechanical strength of the polymer chain as it expands.
• EPDM is one example of such a material.
• the present inventions is an effective way to delay the swelling in either type of element by placing a coating 12 that effectively adheres to the core 10 in downhole conditions.
• a coating 12 that effectively adheres to the core 10 in downhole conditions.
• the powder can be mixed with a solvent such as MEK and the mixture can be referred to as "nitrile cement.”
• the cement coating 12 is applied in a thin layer on the outside of the element 10 and allowed to dry. After it is dry a woven material 14 is tightly wrapped over the coating 12. While Figure 1 shows a spiral wrap other wrapping techniques can be used such as longitudinal strips or parallel circumferential wraps.
• the weave is preferably large rather than tight knit and the assembly is cured in an autoclave for an appropriate time.
• the coating 12 due to the superimposed weave material 14 will develop openings commensurate with the size of the weave.
• gaps in the coating 12 can develop which expose some area of the underlying core 10 while firmly adhering to the remainder of the core 10. This limited access area, whichever way it is provided, will limit the access of water or hydrocarbon or whatever the trigger material is that initiates swelling in the core 10.
• the core 10 swells, it opens up the weave in material 14 to expose more core to fluid that makes it swell.
• the swelling of the core 10 opens bigger gaps between layers of weave material 10 and the swelling of the core 10 accelerates.

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• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• Physics & Mathematics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Sealing Material Composition (AREA)
• Traffic Control Systems (AREA)
• Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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• 2006
  • 2006-07-14 US US11/487,521 patent/US7562704B2/en active Active
• 2007
  • 2007-07-05 CA CA2669778A patent/CA2669778C/en active Active
  • 2007-07-05 GB GB0901808A patent/GB2454608B/en active Active
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• 2009
  • 2009-01-30 NO NO20090476A patent/NO342600B1/no unknown

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